From patchwork Wed Jun 28 11:53:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13295621 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 963FCBA32 for ; Wed, 28 Jun 2023 11:53:54 +0000 (UTC) Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE0C52D58; Wed, 28 Jun 2023 04:53:52 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id 98e67ed59e1d1-262e5e71978so627686a91.1; Wed, 28 Jun 2023 04:53:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687953232; x=1690545232; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=N5FO5w+gMgaN+ODOJl6cUl15G4704GrgV1sKzNYbaTg=; b=dqc1pe2v6MfO/QvQMKrHd5ruJvcE8V9kKcL7a5CDjk5P9pWnrCjjzXevSjauZBYVrj i2WWrfbOjEV4NsiOeKIZfyawTN2rkpyA2ddp+o4QY7otpcC5t+mhMn/YWyMrBlsmw0Ah P2vnnBxx1BG0nfdpbgQY9XWZ8oBf1RYjlH5OZBx+gNs4gEJ7HiNYYQ1puaNrzNrRimQO JQ9aKplKH9hvavLBo+K7gUQBcQAep1l4qPK67lFjiHtbw3b3j2ssWsyMi+hzdh7fMntZ LzcgbVD/1fb31kjOBE0PocnXxSqzQKwTahe+Ai86h4RfkwSIcc3TaihyB091BtF79sM/ DvPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687953232; x=1690545232; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=N5FO5w+gMgaN+ODOJl6cUl15G4704GrgV1sKzNYbaTg=; b=EmQamxkHHb4iYCY9mEMaw6svrFM+fHSm7Gd6fzeOolW3e8ZgVLpqDWsj+Ydg17grau xvpCEdpK3rvAkv7O0QMhWzZzGk9DYUG9q298r4xuOD5VuQ2Ut1YHXXzDttECV7H9aKh2 iYUgHTo2ilvumVZbaOE/ohbo47EOYDK4l6RykBInXbjuE/GFBQHyDmp0ryeRXOy0ioFc HAtrjdTx0qpn/j8H++oUlg5gKwmf5walI2GskYum+Qhj2mtF+pDLn1M0tYDyVjnzfWAD 3/ZoADkEgks1zEuOMMxpPKBYied34YazGiiBREtSomzqlDA+13xXtdzHJAXdvo3v0YhM VTIA== X-Gm-Message-State: AC+VfDyyCd7/ikw5fsHdl6iscOazPL53AowK+8B5thnGJYk5UwhnP/Yo 4RvlrbhdeFMVwJCfJdznTTs= X-Google-Smtp-Source: ACHHUZ5MaS9kWQN3Je7Oznu6GmQb5CrCg5u245wq4j4xC8pVDpF9U5FOaXk/qTqcoNTrGNGwoZtTNg== X-Received: by 2002:a17:90a:1ca:b0:262:c4c2:e29d with SMTP id 10-20020a17090a01ca00b00262c4c2e29dmr1252525pjd.24.1687953232336; Wed, 28 Jun 2023 04:53:52 -0700 (PDT) Received: from vultr.guest ([2001:19f0:ac02:b79:5400:4ff:fe7d:3e26]) by smtp.gmail.com with ESMTPSA id n91-20020a17090a5ae400b002471deb13fcsm8000504pji.6.2023.06.28.04.53.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Jun 2023 04:53:51 -0700 (PDT) From: Yafang Shao To: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, quentin@isovalent.com, rostedt@goodmis.org, mhiramat@kernel.org Cc: bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Yafang Shao Subject: [PATCH v6 bpf-next 11/11] bpftool: Show perf link info Date: Wed, 28 Jun 2023 11:53:29 +0000 Message-Id: <20230628115329.248450-12-laoar.shao@gmail.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230628115329.248450-1-laoar.shao@gmail.com> References: <20230628115329.248450-1-laoar.shao@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net Enhance bpftool to display comprehensive information about exposed perf_event links, covering uprobe, kprobe, tracepoint, and generic perf event. The resulting output will include the following details: $ tools/bpf/bpftool/bpftool link show 3: perf_event prog 14 event software:cpu-clock bpf_cookie 0 pids perf_event(19483) 4: perf_event prog 14 event hw-cache:LLC-load-misses bpf_cookie 0 pids perf_event(19483) 5: perf_event prog 14 event hardware:cpu-cycles bpf_cookie 0 pids perf_event(19483) 6: perf_event prog 19 tracepoint sched_switch bpf_cookie 0 pids tracepoint(20947) 7: perf_event prog 26 uprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 bpf_cookie 0 pids uprobe(21973) 8: perf_event prog 27 uretprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 bpf_cookie 0 pids uprobe(21973) 10: perf_event prog 43 kprobe ffffffffb70a9660 kernel_clone bpf_cookie 0 pids kprobe(35275) 11: perf_event prog 41 kretprobe ffffffffb70a9660 kernel_clone bpf_cookie 0 pids kprobe(35275) $ tools/bpf/bpftool/bpftool link show -j [{"id":3,"type":"perf_event","prog_id":14,"event_type":"software","event_config":"cpu-clock","bpf_cookie":0,"pids":[{"pid":19483,"comm":"perf_event"}]},{"id":4,"type":"perf_event","prog_id":14,"event_type":"hw-cache","event_config":"LLC-load-misses","bpf_cookie":0,"pids":[{"pid":19483,"comm":"perf_event"}]},{"id":5,"type":"perf_event","prog_id":14,"event_type":"hardware","event_config":"cpu-cycles","bpf_cookie":0,"pids":[{"pid":19483,"comm":"perf_event"}]},{"id":6,"type":"perf_event","prog_id":19,"tracepoint":"sched_switch","bpf_cookie":0,"pids":[{"pid":20947,"comm":"tracepoint"}]},{"id":7,"type":"perf_event","prog_id":26,"retprobe":false,"file":"/home/dev/waken/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":21973,"comm":"uprobe"}]},{"id":8,"type":"perf_event","prog_id":27,"retprobe":true,"file":"/home/dev/waken/bpf/uprobe/a.out","offset":4920,"bpf_cookie":0,"pids":[{"pid":21973,"comm":"uprobe"}]},{"id":10,"type":"perf_event","prog_id":43,"retprobe":false,"addr":18446744072485508704,"func":"kernel_clone","offset":0,"bpf_cookie":0,"pids":[{"pid":35275,"comm":"kprobe"}]},{"id":11,"type":"perf_event","prog_id":41,"retprobe":true,"addr":18446744072485508704,"func":"kernel_clone","offset":0,"bpf_cookie":0,"pids":[{"pid":35275,"comm":"kprobe"}]}] For generic perf events, the displayed information in bpftool is limited to the type and configuration, while other attributes such as sample_period, sample_freq, etc., are not included. The kernel function address won't be exposed if it is not permitted by kptr_restrict. The result as follows when kptr_restrict is 2. $ tools/bpf/bpftool/bpftool link show 3: perf_event prog 14 event software:cpu-clock 4: perf_event prog 14 event hw-cache:LLC-load-misses 5: perf_event prog 14 event hardware:cpu-cycles 6: perf_event prog 19 tracepoint sched_switch 7: perf_event prog 26 uprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 8: perf_event prog 27 uretprobe /home/dev/waken/bpf/uprobe/a.out+0x1338 10: perf_event prog 43 kprobe kernel_clone 11: perf_event prog 41 kretprobe kernel_clone Signed-off-by: Yafang Shao Reviewed-by: Quentin Monnet --- tools/bpf/bpftool/link.c | 247 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 246 insertions(+), 1 deletion(-) diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index ba67ea9d77fb..7c4c9fc45f63 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -17,6 +17,8 @@ #include "main.h" #include "xlated_dumper.h" +#define PERF_HW_CACHE_LEN 128 + static struct hashmap *link_table; static struct dump_data dd = {}; @@ -279,6 +281,110 @@ show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr) jsonw_end_array(json_wtr); } +static void +show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_KRETPROBE); + jsonw_uint_field(wtr, "addr", info->perf_event.kprobe.addr); + jsonw_string_field(wtr, "func", + u64_to_ptr(info->perf_event.kprobe.func_name)); + jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset); +} + +static void +show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_URETPROBE); + jsonw_string_field(wtr, "file", + u64_to_ptr(info->perf_event.uprobe.file_name)); + jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset); +} + +static void +show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + jsonw_string_field(wtr, "tracepoint", + u64_to_ptr(info->perf_event.tracepoint.tp_name)); +} + +static char *perf_config_hw_cache_str(__u64 config) +{ + const char *hw_cache, *result, *op; + char *str = malloc(PERF_HW_CACHE_LEN); + + if (!str) { + p_err("mem alloc failed"); + return NULL; + } + + hw_cache = perf_event_name(evsel__hw_cache, config & 0xff); + if (hw_cache) + snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache); + else + snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff); + + op = perf_event_name(evsel__hw_cache_op, (config >> 8) & 0xff); + if (op) + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%s-", op); + else + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%lld-", (config >> 8) & 0xff); + + result = perf_event_name(evsel__hw_cache_result, config >> 16); + if (result) + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%s", result); + else + snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str), + "%lld", config >> 16); + return str; +} + +static const char *perf_config_str(__u32 type, __u64 config) +{ + const char *perf_config; + + switch (type) { + case PERF_TYPE_HARDWARE: + perf_config = perf_event_name(event_symbols_hw, config); + break; + case PERF_TYPE_SOFTWARE: + perf_config = perf_event_name(event_symbols_sw, config); + break; + case PERF_TYPE_HW_CACHE: + perf_config = perf_config_hw_cache_str(config); + break; + default: + perf_config = NULL; + break; + } + return perf_config; +} + +static void +show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr) +{ + __u64 config = info->perf_event.event.config; + __u32 type = info->perf_event.event.type; + const char *perf_type, *perf_config; + + perf_type = perf_event_name(perf_type_name, type); + if (perf_type) + jsonw_string_field(wtr, "event_type", perf_type); + else + jsonw_uint_field(wtr, "event_type", type); + + perf_config = perf_config_str(type, config); + if (perf_config) + jsonw_string_field(wtr, "event_config", perf_config); + else + jsonw_uint_field(wtr, "event_config", config); + + if (type == PERF_TYPE_HW_CACHE && perf_config) + free((void *)perf_config); +} + static int show_link_close_json(int fd, struct bpf_link_info *info) { struct bpf_prog_info prog_info; @@ -334,6 +440,26 @@ static int show_link_close_json(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_KPROBE_MULTI: show_kprobe_multi_json(info, json_wtr); break; + case BPF_LINK_TYPE_PERF_EVENT: + switch (info->perf_event.type) { + case BPF_PERF_EVENT_EVENT: + show_perf_event_event_json(info, json_wtr); + break; + case BPF_PERF_EVENT_TRACEPOINT: + show_perf_event_tracepoint_json(info, json_wtr); + break; + case BPF_PERF_EVENT_KPROBE: + case BPF_PERF_EVENT_KRETPROBE: + show_perf_event_kprobe_json(info, json_wtr); + break; + case BPF_PERF_EVENT_UPROBE: + case BPF_PERF_EVENT_URETPROBE: + show_perf_event_uprobe_json(info, json_wtr); + break; + default: + break; + } + break; default: break; } @@ -505,6 +631,75 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info) } } +static void show_perf_event_kprobe_plain(struct bpf_link_info *info) +{ + const char *buf; + + buf = (const char *)u64_to_ptr(info->perf_event.kprobe.func_name); + if (buf[0] == '\0' && !info->perf_event.kprobe.addr) + return; + + if (info->perf_event.type == BPF_PERF_EVENT_KRETPROBE) + printf("\n\tkretprobe "); + else + printf("\n\tkprobe "); + if (info->perf_event.kprobe.addr) + printf("%llx ", info->perf_event.kprobe.addr); + printf("%s", buf); + if (info->perf_event.kprobe.offset) + printf("+%#x", info->perf_event.kprobe.offset); + printf(" "); +} + +static void show_perf_event_uprobe_plain(struct bpf_link_info *info) +{ + const char *buf; + + buf = (const char *)u64_to_ptr(info->perf_event.uprobe.file_name); + if (buf[0] == '\0') + return; + + if (info->perf_event.type == BPF_PERF_EVENT_URETPROBE) + printf("\n\turetprobe "); + else + printf("\n\tuprobe "); + printf("%s+%#x ", buf, info->perf_event.uprobe.offset); +} + +static void show_perf_event_tracepoint_plain(struct bpf_link_info *info) +{ + const char *buf; + + buf = (const char *)u64_to_ptr(info->perf_event.tracepoint.tp_name); + if (buf[0] == '\0') + return; + + printf("\n\ttracepoint %s ", buf); +} + +static void show_perf_event_event_plain(struct bpf_link_info *info) +{ + __u64 config = info->perf_event.event.config; + __u32 type = info->perf_event.event.type; + const char *perf_type, *perf_config; + + printf("\n\tevent "); + perf_type = perf_event_name(perf_type_name, type); + if (perf_type) + printf("%s:", perf_type); + else + printf("%u :", type); + + perf_config = perf_config_str(type, config); + if (perf_config) + printf("%s ", perf_config); + else + printf("%llu ", config); + + if (type == PERF_TYPE_HW_CACHE && perf_config) + free((void *)perf_config); +} + static int show_link_close_plain(int fd, struct bpf_link_info *info) { struct bpf_prog_info prog_info; @@ -553,6 +748,26 @@ static int show_link_close_plain(int fd, struct bpf_link_info *info) case BPF_LINK_TYPE_KPROBE_MULTI: show_kprobe_multi_plain(info); break; + case BPF_LINK_TYPE_PERF_EVENT: + switch (info->perf_event.type) { + case BPF_PERF_EVENT_EVENT: + show_perf_event_event_plain(info); + break; + case BPF_PERF_EVENT_TRACEPOINT: + show_perf_event_tracepoint_plain(info); + break; + case BPF_PERF_EVENT_KPROBE: + case BPF_PERF_EVENT_KRETPROBE: + show_perf_event_kprobe_plain(info); + break; + case BPF_PERF_EVENT_UPROBE: + case BPF_PERF_EVENT_URETPROBE: + show_perf_event_uprobe_plain(info); + break; + default: + break; + } + break; default: break; } @@ -575,11 +790,12 @@ static int do_show_link(int fd) struct bpf_link_info info; __u32 len = sizeof(info); __u64 *addrs = NULL; - char buf[256]; + char buf[PATH_MAX]; int count; int err; memset(&info, 0, sizeof(info)); + buf[0] = '\0'; again: err = bpf_link_get_info_by_fd(fd, &info, &len); if (err) { @@ -614,6 +830,35 @@ static int do_show_link(int fd) goto again; } } + if (info.type == BPF_LINK_TYPE_PERF_EVENT) { + switch (info.perf_event.type) { + case BPF_PERF_EVENT_TRACEPOINT: + if (!info.perf_event.tracepoint.tp_name) { + info.perf_event.tracepoint.tp_name = (unsigned long)&buf; + info.perf_event.tracepoint.name_len = sizeof(buf); + goto again; + } + break; + case BPF_PERF_EVENT_KPROBE: + case BPF_PERF_EVENT_KRETPROBE: + if (!info.perf_event.kprobe.func_name) { + info.perf_event.kprobe.func_name = (unsigned long)&buf; + info.perf_event.kprobe.name_len = sizeof(buf); + goto again; + } + break; + case BPF_PERF_EVENT_UPROBE: + case BPF_PERF_EVENT_URETPROBE: + if (!info.perf_event.uprobe.file_name) { + info.perf_event.uprobe.file_name = (unsigned long)&buf; + info.perf_event.uprobe.name_len = sizeof(buf); + goto again; + } + break; + default: + break; + } + } if (json_output) show_link_close_json(fd, &info);